Clinical outcomes of remnant preserving augmentation in anterior cruciate ligament reconstruction: a systematic review

Purpose The objective of this study was to systematically review the current evidence to see whether the remnant preservation techniques could obtain better clinical outcomes than the standard anterior cruciate ligament reconstruction procedure. Methods The authors systematically searched online databases to identify the studies which compared the remnant preservation techniques with the standard techniques. Two reviewers independently extracted data and evaluated the methodological quality of each study. Clinical outcomes in terms of knee stability, clinical scores, vascularization, proprioception, tibial tunnel enlargement and complications were qualitatively compared. Results Thirteen studies met the inclusion criteria for review. Compared with the standard procedure, significantly better results regarding knee stability in the remnant preserving group were reported in two of nine studies in the instrumented knee laxity, one of eight studies in the Lachman test and none of eight studies regarding the pivot shift test. Five studies assessed International Knee Documentation Committee scores but found no differences. One of two studies indicated significantly earlier revascularization according to the signal/noise quotient value of the graft on magnetic resonance imaging. One of two studies indicated significantly better proprioceptive function in terms of joint position sense using the reproduction of passive positioning test. Two of two studies showed significantly less tibial tunnel enlargement in the remnant preserving group. None of the studies showed significant increase in the risk of cyclops lesion formation and the loss of knee range of motion in the remnant augmentation group. Conclusions The current evidence suggests that the short-term clinical outcomes of patients with the remnant augmentation technique are comparable, if not superior, with that of patients undergoing the standard technique, although it is insufficient to justify the remnant preserving augmentation as a routine treatment for anterior cruciate ligament ruptures. Level of evidence Systematic review, Level IV.